Shock absorber



April 3, lzf

H. R. HUGHES, JR

snocx Asonsn 19d Jan. 9. 1924 v i z2 .as :z

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22 l .9 3l J 0 s o o l 0o 3J o o o.

,n 2 le .il 17 O O z O- O kao Patented pr. 3, 1,928.

1,664,510 PATENT y OFFICE.

' rkHowARD n. HUGHES, an., or HoUsToN, TEXAS.l y

SHOCK ABSORBER.

Application led January `9, 1924. Serial No. 685,103.

My invention vrelates to shock absorbers oruse on motor vehicles. Itis particularly applied to shock absorbers of the pneumatic type wherein a cushion of Vair under pressure is used to sustain the weight of the ve? hicle body. I. Y

An object of the invention 1s to provide a pneumatic shock absorber having a large working volume of the pressure luid above.

struction will become apparentirom theI more detailed description ,which follows. Referring tothe drawing herewith wherein ,a preferred embodiment ot the invention is disclosed, Fig. 1 is a central vertici-al section through the cylinder and housings ot my in- Y vention shown as applied to the frame ot a vehicle. Fig. 2 isa broken detail in central .section through the dash pot employed with the pressure regulating mechanism.v Like` numerals of reference are employed to designate like parts vin both the views. .g 'f

In the 'drawing I have shown mydevice somewhat diagrammatically as supported upon the vehicle frame or chassis 1, said frame being supported upon a housing 2.

surrounding theaxle 3. The -vertical .supporting connection between the axle housing andthe frame work is made .entirelyvby my pneumatic shock yabsorbing device. A bracket 4, clamped yabout thehousing is extended upwardlyfor connection at 5 with a piston rod 6 having on its upper end a piston 7, working within a cylinder 8.

The said cylinder is secured to the inner side of the frame 1 by means of brackets 9,y in position vertically above the' supporting bracket 4 of the piston rod. The cylinder is open at its lower end and closed at its upper end, except for an opening 10 connected by means of a pipe 11 with a storage tank 12. This connection ot` the cylinder with the storage tank has the effect of enlarging the volume of the cylinderV above the piston.

The chamber 13 above the piston may be connected through a pipe 14 with a pressure tank 15, which in'turn is connected through a pipe 16 with a pump 17. It is contemplated that the pressure Within the tank` may be maintained at a predetermined amount by automaticallyl regulated means nal position.

upon the pump 17. This arrangement is common in thea-rt and is not specifically illust-rated. f

The connection between the cylinder chamber 13 and the pipe 14 is by way of a valve chamber 18 formed inthe thickened Walls of the housing 19. This chamber has at the upper end a perforated plug'20 and at its lower end a similar plug 21 through which works a valve stem 22. Said valve stem has within the valve chamber l18 two piston valves 23 spaced apart a predeterl mined distance so that normally the upper piston closes the connection between the chamber and the pipe 14. yThe lower piston valve closes an outlet passage 24 which '.forms a discharge port for air under pressure when the pressure isto be relieved. A passage 25 connectsl the upper end of the .chamber 13 tothe valve chamber 18.

The valve stem 22 is extended downwardly'to a point adjacent thefaxle` 3 and has thereon a washer or ring 26 secured adjustf ably thereto. Above the ringl 26 is a spiral spring 28 which bears at its upper end against a sleeve `29 securedon the forward end of'an arm 30 which is rigidly secured to the piston rod 6 by means of set screws 31. 'Above the sleeve 29 is a similar spring 32v lwhich bears against said sleeveatits lower end and against a ring or washer 33 at its upper end, said ring being securedY adjustably torsaid rod. The valve stem is slidable through the sleeve 29 and through acylindrical chamber 34.` Withinthis chamber there is .secured to the valve stem a perfo,-

rated disc or platew35V whichforms a piston within the. cylinder 34 to form a dash pot.

A lThe wallsv of the dash pot are thickened at one sideI and formedy with a by-pass r36v connectingtheopposite ends of the cylinder. 'In said passage` 36 is a handv operated valve k37 by means of which the passage of 4liquid through` the by-pass may beregulated. f In the operation of this device the pressurey above the piston will be so regulated-as, to support the weight of the vehicle in proper spaced relation above the axle.V When additional weight is placed upon the vehicle body, due to passengers getting into the -vehicle and otherwise7 the tendency will be for 'the frame 1 to` be forced downwardly toward the axle, forcing the piston 7 upwardly into the cylinder of the shock absorber to a point somewhat above its origi This vmotion will be trans-l mitted also to the valve rod 22, thus forcing theupper piston 38 of the valve above the opening to the pipe 14 and allowing air under pressure tov enter through the valve chamber and the 'passage 25 to the chamber 13 above ythe piston. This inlet of air under pressure will continue until the piston 7 is 'forced downwardly relative to the fra-ine,

'carrying with it the valve stern 22 and finally closing theinlet from the nine. 14 and shutting 'oil the entrance o'l further air from the pressure tank. This action will be entirely automatic and as the loadthus placed 18. This will open theoutlet port 24. The

plug 21 will prevent movement downwardly of valve 23 suili'ciently to expose pipe 1&1 tok exhaust above valve piston 38. Exhaust oi air will continue until the pressure above the piston 7 isregulated in such manner that the exhaust ports are again closed.

In theordinary conditions of trafiic along a roadway there will be shocks delivered Y' through tliefwheel and axle upwardly to* ward the *frame due to thepassage 'of the wheel over bumps or irregularities in the roadway. Such a shock would be delivered upwardly by the piston 7 against thecushion of air `above it, and as this cushion of air Y has a large volume it would not materially compress' this volume and hence there would be slight tendency toward recoil. The wheel would again drop back after passage over the buinp toits original position without materially affecting the `position of` the carv body. This sort of action will not affect the valve rod 22 due to the resilient connection of the said rod with thepiston rod 6 and also'to the dampening `etect of the dash pot 34. The springs 28 and 32 will absorb this motion and the dash pot, due to its sluggish action, will overcome any tendencyof the valve rod to move quickly. The result will be that the ordinary vibrations of' trailic will not be transmitted to the valve pistons 23 and 38 and no action of eitherwill take place.

The advantage of this type of shock absorber lies in the fact that ordinary shock lorvibrations due to passage over the roadway will not be transmitted to the frame of the car. The tendency will be for the car iframe to be held in the saine relative horizontal position. There will be no recoil in a shock absorber of this kind, as is the case where springs are used. Furthermore, the shock absorber will automatically adjust itself for heavy or light loads. and the tendency ofthe shock absorber to work rdiderf ently vunder varyingloads w'ill be avoided. The further advantages of this construction will be readilyv understood by one skilled in the art without furtherdescriptions.

llVhat I claim as new aiid'dcsire'to protect by Letters Patent is:

1. In a vehicle including a frame Vand axle, a cylinder, a piston in said cylinder,

a rod on said piston, said cylinder and pis-V ton being connected between said frame andV axle, a tank'for air under pressure, a'pipe connectingl the tank and said cylinder beyoiid'said piston, va valve in said'pipe, a

Lvalve stein on said valve having resilient connection with said piston andk a" dash pot Y ou said stem acting to resist movement'oit said stem and valve, said valve controlling the air to said cylinder to maintain'V the nor'- nial position of said piston therein.

2. In a vehicle including a traine and axle, a cylinder on saidl frame closed at its upper end, a piston iii said cylinder supported upon said axle, a pressure tank for airlinder pressure, a pipe from said tank connect? ing with said cylinder above said piston,lan automatically controlled valve in said pipe,

and resilient'means to daiiipciiv'tlie Vaction of said valve. y

In testimony whereof, .l hereunto aiiix my signature this 14th day oif January, A1. D. 1928."

HOWARD R.V HUGHES. 1 

